The invention relates to a method of producing a plate-shaped product comprising positioning a component which is connected to or forms part of a plate which at the position of the component is supported by a support. A die forms the component from the plate or positions a discrete component on the plate. To this end, the term "positioning" a component means both placing a discrete component or forming a component, and thus, also placing a component, from a sheet material portion at a given sheet location. The invention also relates to a device suitable for carrying out the method and a plate-shaped product manufactured according to the method. In this context the component is considered as a part of a plate or as a discrete element. In case the component is a part of the plate this part has to be deformed at the desired position. In this case the die is intended to mean a deforming member. In case the component is a discrete element connected to the plate, the die does not deform anything but only changes the position of the discrete element with respect to the plate so the die is intended to mean an element positioning member.
A method and device of the type mentioned in the preamble are generally known in the form of a compression device provided with a top and bottom die. In such a known compression device a plate is placed on the bottom die, and the top die is then pressed against the plate in such a way that the plate deforms permanently. During the compression the plate will not only deform plastically, but a certain elastic deformation of the plate will also occur. After lifting of the top die the plate will spring back to some extent as a result of the elastic energy in the plate. This means that the final shape of the plate differs slightly from the shape of the dies. This problem is partly solved by taking the elastic springback into account and deforming the plate slightly more, but the basic shape of the plates to be deformed is not the same for all plates, which means that some plates deform elastically more than other plates, and consequently deviations in shape between the individual pressed plates will in the end still be present, albeit smaller. If the plates are intended for use as chassis plates on which components which have to be positioned very accurately relative to each other are being mounted, the positions of these components will have to be adjusted again after fitting, since deviations in the positions of the components occur through the shape tolerances of the chassis plate.
This state of affairs also occurs during the production of chassis plates for video recorders. In the case of video recorders very high standards are set for the relative positions of, inter alia, the scanning unit, the capstan and the tape guides. The required accuracy lies in the order of micrometers. Through the elastic springback of the plate, deviations of the order of tens of micrometers do, however, occur. For this reason the components are fitted in such a way that their positions are readjustable. This readjustment is costly and time-consuming.
A chassis plate in which the mounting faces for the components to be fitted are positioned accurately relative to each other is known from European Patent Application EP 0 184 159 A2. In this case the chassis plate is cast, and the mounting faces are finished in one setting. The disadvantage of this chassis plate is that the manufacture thereof is very laborious, and is therefore also costly. The cast structure also means that the plate is heavy and the material costs are high.